ISO 696:1975 pdf free
ISO 696:1975 pdf free.Surface active agents – Measurement of foaming power – Modified Ross-Miles method
Measuring cylinder of 1 I capacity, complying with ISO… with graduations at each 10 ml. The measuring cylinder stands in a water bath fitted with a thermostat, the bath being sufficiently large to accommodate the measuring cylinder immersed up to half its height.
Stand comprising a vertical rod, sufficiently long to allow the separating funnel and the measuring cylinder to be held in place. To ensure that the assembly is centred and so maintained during the measurement, the separating funnel is held by means of a ring supporting the spherical part, and a clamp placed as low as possible around the stem of the separating funnel, near the tap. The measuring cylinder is held in place by means of a screw-clamp with one movable jaw.
Metering tube, stainless steel, 70 mm long, 1,9±0,02 mm internal diameter and 0,3 mm wall thickness. The ends of the tube shall be cut accurately at right angles to the axis of the tube, on a precision tool lathe.
The metering tube is a push fit in a steel mounting tube 5 to 10 mm long, of internal diameter equal to the external diameter of the metering tube, and of external diameter equal to that of the low end of the glass tube of the separating funnel. The upper ends of the metering tube and of the mounting tube shall be in the same plane. The mounting tube is fixed by means of a short length of thick rubber tube (vacuum tubing) so that the upper end of the mounting tube is in contact with the lower end of the glass tube.
Keep the mounting tube and metering tube assembly for 30 min in the vapour of an azeotropic mixture of ethanol and trichlorethylene, then rinse it with a small quantity of the solution under test.
Between successive measurements, on the same product,simply rinse the apparatus with the solution under test.When it is required to remove the foam remaining in the measuring cylinder, no matter what method is employed to do so, follow by a rinse with the solution under test.ISO 696 pdf download.
